Nanocomposite coatings of poly(3-Fluoro-p-anisidine)/modified polyethersulfone filled with graphene

Abstract

This study reports on novel corrosion protection polymer/graphene nanocomposite coatings. Owing to the potential of conducting polymers in corrosion inhibition, poly(3-Fluoro-p-anisidine) (PFANI) was synthesized by in situ polymerization using ammonium persulfate. Polyethersulfone was also modified to form mod-PES. Afterward, PFANI was blended with modified polyethersulfone to form PFANI/mod-PES blend. Graphene, a nano-allotrope of carbon, possess excellent corrosion inhibition properties to be employed in polymeric coatings. In this attempt, graphene was prepared by reducing graphene oxide with hydrazine hydrate. PFANI/mod-PES blend was reinforced with graphene using solution mixing route to develop a series of PFANI/mod-PES/G nanocomposite. Field emission scanning electron microscopy (FESEM) represent seamlessly aligned crimped graphene nanosheet dispersion in the matrix. Transmission electron microscopy (TEM) depicted transparent 2D nanosheet morphology without any agglomeration. The thermal stability of PFANI/mod-PES/G 0.1–5 nanocomposite was significantly improved with the graphene nanofiller loading compared with the neat blend. Inclusion of 5 wt.% graphene loading caused maximum enhancement in thermal properties, i.e. initial weight loss (T₀), 10% degradation temperature (T₁₀), and maximum decomposition temperature (T_max) of 472, 537, and 612 °C, respectively. Moreover, electrical conductivity of PFANI/mod-PES/G 0.1–5 was found higher at 100 °C (1.1–2.1 S cm⁻¹) relative to room temperature values (10⁻³–1.5 S cm⁻¹). The corrosion behavior was investigated using weight loss method, corrosion rate study, open circuit potential, visual test, and electrochemical impedance measurements. Corrosion tests have shown that the inclusion of graphene nanofiller considerably enhanced the protection against corrosive media (3.5% NaCl solution) by preventing the underlying metal.

Graphical Abstract

Keywords:

• Graphene
• poly(3-Fluoro-p-anisidine)
• polyethersulfone
• electrical conductivity
• corrosion protection

Disclosure statement

No potential conflict of interest was reported by the author.